OpenAL (was Re: GLUT and sound)

["Adam D. Moss" <adam@gimp.org>]

Stephen J Baker wrote:
> > How much good is OpenAL?
> > Is the project still under developement, or is it near to death?
> It doesn't seem to have changed much (at all?) since Loki died...they
> were the major drivers behind it.
OpenAL is still alive and has a (distracted but not-dead) Linux
maintainer.  The Linux CVS version has a trickle of fixes committed.

I think the fundamental lack of motion on it is that it's pretty
much 'done' as far as the Linux software reference implementation
goes.  Yeah, it works and is deployed in various products (Linux,
Windows, almost certainly MacOS).

Windows has native hardware OpenAL drivers for Creative cards and
nVidia nForce chipsets, plus a generic DirectX-backend version
(this is the Creative version when running on non-Creative hardware)
which may or may not use hardware 3d mixing if available.  The
current Unreal Tournament(2003) engine supports OpenAL as its
preferred audio back-end on all platforms I believe.

Linux's OpenAL can use a number of audio back-ends (ALSA, OSS,
etc), but AFAIK all of them mix in software (a hardware
emu10k1 back-end is still in the tree, but broken).  The speed
of the software mixer is unimpressive but not bad.  Linux's
OpenAL can also output to an SDL audio back-end (albeit in
two channels max), essentially making it portable in this
respect to all platforms supported by SDL.

What I think is needed to drive OpenAL on the Linux front is a
not-reference implementation with a more proactive stance in
terms of extensions and optimization.  Either someone picks up
the reference implementation (or the Creative implementation, which
is also open source!) and runs with it, or writes an implementation
from scratch based on the spec.  (I'd like to have a go, though it'll
most likely have to wait until I'm caught up with the work that
[doesn't currently] put bread on my table.)

But in summary, OpenAL is done and deployed, and by dint of not
actually _requiring_ vendor support for current or future
satisfactory operation, there's little risk posed by using it.

--Adam
--
Adam D. Moss   . ,,^^   adam@gimp.org   http://www.foxbox.org/   co:3
"I am NOT a nut!  I am the keeper of the seven universal truths!"